Jam Sessions makes use of the DS touch screen to simulate strumming on a real guitar, while the D-pad is used for selecting chords. The game allows players to play through a list of songs in order to unlock other features such as upgraded strings and new backgrounds, while Free Play allows the player to simply strum away, playing out songs or practicing without being judged. Tutorial and Warm Up modes teach players how to play the game and get accustomed to the controls and the concepts behind playing guitar.
What makes Jam Sessions different from other rhythm games, such as Guitar Hero, is that it is considered to be a tool instead of a game. In addition, the player (while using headphones or an external speaker) can also use the DS microphone to sing along. Andy Myers of Nintendo Power and his band, Hidari Mae demonstrated this ability by writing and recording a song using Jam Sessions for guitar alongside traditional instruments.
The DS can also be plugged into an amplifier via the headphone jack to output a more natural sound. A Jam Sessions "Performance Bundle" was set to be released on January 4, 2008 and was going to include a portable amplifier in addition to the game. The bundle has since disappeared from Ubisoft's web page.